After you file the complaint, you begin to analyze your legal strategy. The case involves whether or not Oily, Inc, is violating a state statute that forbids gradual rather than "sudden and accidental" release of pollutants. In researching the issue of whether or not your seepage is "sudden and accidental," you have found an opinion by the Ohio Supreme Court defining "sudden and accidental" in a case with similar facts. What type of law is the opinion?